tonight an ABC news exclusive. Our Diane sawyer going one-on-one with New Jersey governor Chris Christie, the man once consider considered the republican party's best hope to capture the white house in 2016 now finds himself embroiled in scandal after his top aides ordered traffic lanes shut down in an act of political revenge. So did Christie know about it? Should he have? And can he still run for president? Here's what he told Diane. It was thscandal that threaten to derail the gor nor of New Jersey, the no-nonsense tough-talking Chris Christie. You know, something may go down tonight but it ain't going to be jobs, sweetheart. A rising political star with national aspirations. For four days strigt drivers used to 30 minute commutes faced two to three two four-hour gridlo gridlock. Children in school buses, desperate people making calls to 911. It's an emergency. And they are not there. Could this all be political payback for a local mayor who hadn't supported Christie's re-electi re-election? Then we read text messages showing some of Christie's aides seeming to be chortling. Tonight, some of those who wrote those e-mails still have not talked about what they've said or didn't say to governor Christie. One of them, Bridget Kelly. Another, David wildstein, rumbling about getting immunity. But until they do, the governor points out a new report issued today clears him, and he sat down with me in his family home to explain why. This report says that I had no knowledge of it before it happened. Nor did I authorize it. Or have anything to do with it. And that's the truth. But does it make you feel clueless? Did it make you feel like what was wrong with me? Not clueless, but it certainly makes me feel taken advantage of and also more importantly, I feel like I let people down. By not knowing. Sometimes people do inexplicably stupid things. But critics point out the report was commissioned by the Christie administration itself. I want to get to what everybody is saying about this report. Words are used, whitewash, expensive scam that the tax pairs hapair ers of New Jersey paid for your lawyers to find you blameless. First off, these are not my lawyers. But it's the law firm that you've been affiliated with in the past. You knew one of the partners. Chosen by the office. There's hardly a law firm in this area that I haven't had sfwer action with being the United States attorney. But the bottom line is these people have their own professional and personal reputations. They're not going to whitewash anything for me. David wildstein, a transportation official said he once told Christie something about traffic. David wildstein has said that at a 9/11 event he talked to you about traffic. It's a little ambiguous exactly what. Did he? I don't have any recollection of that, Diane. David was one of hundreds of people I spoke to that day. I don't have any recollection of him saying anything. But I tell you this, he didn't say by the way, governor, I'm closing down some lanes on the George Washington bridge to stick it to the mayor. Is that okay? That I would remember. But critics remember the lure of Christie's brash personal style. I'm governor, could you just shut up for a second? If you disagree, he's going to get you, he's going to stamp you out. He's going to seek revenge. The governor has certainly conduct ed himself over the last four years as the worst combination of a bully and boss. As you know, the word bully and bullying comes up over and over again. Have you asked yourself, did I do anything to create the climate in which this happened? Sure. I spent a lot of time the last 11 weeks thinking about what did I do, if anything, to contribute to this. I don't believe I did, but I'm certainly disappointed in myself that I wasn't able to pick up these traits in these people. You don't think there's a single possibility that they thought in rough and tumble style in Jersey politics style, that they thought this would please you? No. That this was for you? No. I don't believe it was for me. What did you say to your children? What did you say? Our oldest son was home on break and he asked me, did you do this? It was a tough question. That your son would ask you. And I said no, I didn't. And he said good. I'm glad. Is it a change of the leadership style? No. I am who I am. And for some people, they love it. I will tell you, when I travel around New Jersey I hear from most people, that's the thing they love the most. What about Iowa? Oh, I think they love me in Iowa, too, Diane. I've been there a lot. I think they love me there, too. Has this been the toughest time in your life? Toughest time in my professional life. Not my personal life. Did you think at any point, maybe I should step down, this is too much. Never. Never. I'm not a quitter. For "Nightline," I'm Diane sawyer here in New York. Not a quitter. Fascinating interview. And our thanks to Diane sawyer tonight.

This transcript has been automatically generated and may not be 100% accurate.